This invention relates generally to gas turbine engines and more specifically, to a method and apparatus for modeling a gas turbine engine that includes a pulse detonation system.
At least some known pulse detonation systems use a series of repetitive detonations within a detonation chamber to produce a high pressure exhaust. More specifically, a fuel and air mixture is periodically detonated within a plurality of tubes, or other geometric configurations, such as an annular chamber, positioned within the detonation chamber to cause a strong shock wave to propagate at supersonic speeds through the unburned fuel-air mixture. The passage of the strong shock wave causes a mode of combustion, known as detonation, to occur behind, and closely coupled to, the strong shock wave, a condition herein referred to as the detonation wave or the detonation front. More specifically, the detonation wave increases the temperature and pressure within the combustion gases. The products of combustion exit the tube or annular chamber at an elevated pressure and temperature, and at a high velocity. The pressure, temperature, and velocity of the gases exiting the detonation chamber are higher than would be obtained with conventional gas turbine combustion.
At least some known pulse detonation systems are used as a core engine system for a gas turbine engine. Other known pulse detonation systems are used to augment conventional gas turbine engines. More specifically, a conventional gas turbine engine may include a core engine system that typically includes in serial, axial flow relationship, a compressor, a combustor, a high pressure turbine, and a low pressure turbine. Some known pulse detonation systems are positioned downstream from the core engine system to facilitate increasing thrust by providing additional energy to exhaust airflow exiting the core engine system and a bypass duct surrounding the core engine.
Known methods for modeling pulse detonation system performance and design characteristics include determining time-stepped solutions for a particular pulse detonation system. However, such methods only model the pulse detonation system, and may not obtain additional data regarding operating conditions within the system for a plurality of flight conditions.